A servo controller controls the actuation of a servo motor, and a servo motor feeds back a control state such as positional information to the servo controller. The servo controller computes a control value of the servo motor based on the information that is fed back, and the computed control value is transmitted to the drive circuit of the servo motor. The servo controller is capable of transmitting and receiving an input signal from the drive circuit or an output signal to the drive circuit for each predetermined period. Therefore, as described in the following patent literature, the servo controller computes the control value, that is, the output signal based on information relating to the control state of the servo motor which has been acquired immediately before, that is, the input signal which is received within one period. The servo controller transmits the computed control value to the drive circuit after holding the control value for a shorter time than one period or without holding the control value. Accordingly, the servo motor actuates according to the control value.